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To: "Kenneth D. Merry" <ken@kdm.org>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Fri, 29 Aug 2003 22:03:57 MDT."
             <20030830040357.GA42770@panzer.kdm.org> 
Date: Sat, 30 Aug 2003 09:22:10 +0200
Message-ID: <3821.1062228130@critter.freebsd.dk>
cc: current@FreeBSD.org
Subject: Re: need some debugging help 
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In message <20030830040357.GA42770@panzer.kdm.org>, "Kenneth D. Merry" writes:

>I think I have everything setup correctly, but I keep getting panics inside
>the GEOM code with these patches.  (Memory modified after free.)  I don't
>know whether I've just exposed some race condition, or whether I've done
>something wrong.

Do you have any idea what goes on at/right before the panic ?

Ie: has drives been created [disk_create()] or removed [disk_destroy()]
right before ?

My best shot, would be that disk_destroy() was called and something
somehow fiddled the related structures subsequently.

You may want to set kern.geom.debugflags=N and see if that offers
any clues.

	N |= 1  topology events
	N |= 2  bio processing (ie: many lines for each I/O)
	N |= 4  access processing (open/close)

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.